Is this a joke?

Theorem:  Spacetime has two spacelike dimensions at our current location in spacetime.

Proof: Modern day physics is based on Quantum Theory.  Quantum Theory is incompatible with gravity in three spacelike dimensions. To describe gravity one must look at the Poincare dual which has one less spacelike dimension, i.e., two rather than three.  Hence, the third spacelike dimension is unphysical. Of course, it is possible to use frameworks like the M-theory framework utilizing additional unphysical dimensions.  But this is irrelevant, since at the present time, the only realistic theory that utilizes this framework is Quantum Theory.  QED (at our current location).

Hypothesis: There must be something wrong with the way mathematics is taught in schools, if some students cannot imagine spacetime as having only two dimensions plus time.

Question: How do you visualize the chiral structure of graphene and time reversal symmetry?  Can you visualize one layer of graphene being deposited on another in such a way as to retain the symmetries, but reduce the propagation speed of the charge conductors?  Can you image graphene being made into nanotubes as a two dimension material being transformed into a one dimensional material? Can you imagine a nanoplatelet of graphane oscillating between the annealed and annealed state travelling through a light hydrogen filled, enriched nickel nanotube?  Would you gasp if your best friend asked you these questions? Why???